The Avon Maitland District School Board didn't learn of the breach until a former student found the information online.

The exposed data includes the students' names, Ontario education numbers, birthdates, genders, final grades, learning skills and work habit assessment scores, and days absent. All high school students from the 2008-2009 school year are affected, except for those at Mitchell District High School.

"While it shouldn't have been out there, it's not enough information, we feel, for identity theft," school district manager of communications Steve Howe told the Beacon Herald. "It's not complete enough to do anything with."

"We did have forensic computer people look into it to see how many times it was accessed," Howe added. "There's no definitive number but it doesn't appear it generated much traffic."

In response to the incident, the school board says it's reviewing its information security procedures and training staff on the handling of private information.